1. Technical Field
The present invention relates to an image display device, an image display method, an image display program a recording medium containing the image display program, and an electronic apparatus, which execute a process on input image data.
2. Related Art
In an existing image display device, such as a laptop computer, that uses a non-luminescent display device, such as a liquid crystal panel, when electric power is not supplied from the outside, image display is performed in such a manner that a light source (for example, cold-cathode tube) converts electric power supplied from a battery to light and the amount of light transmitted through the liquid crystal panel is then controlled. In general, of electric power consumed in the whole device, a percentage of electric power consumed by the light source is relatively large. Then, during battery driving, electric power consumed by the device is reduced by reducing the amount of light emitted from the light source (hereinafter, referred to as “the amount of source light”).
Here, when the amount of source light is controlled in a case where the amount of source light steeply varies, it has been known that a display screen flickers (hereinafter, referred to as “flicker”). In order to prevent such a flicker, the following technologies have been proposed. Japanese Unexamined Patent Application Publication No. 11-65528 describes a technology that attempts to reduce power consumption by light control and expand a dynamic range, white moderating a change in maximum value of an image by a high-frequency cut filter in order to prevent a flicker due to the light control. In addition, Japanese Unexamined Patent Application Publication No. 2004-4532 describes a technology that changes a light source control characteristic on the basis of the result of comparison between an input video signal and the previous output signal. Other than the above, Japanese Unexamined Patent Application Publication No. 2004-282377 describes a technology related to the invention.
However, in the technology described in the above JP-A-11-65528, the rate of change in light control is not dependent on a change of scene in a screen image, so that there is a possibility that, when there is no change of scene, a change due to light control is easily noticed or, on the other hand, when a change of scene is steep, light control is not able to follow the change. In addition, in the technology described in JP-A-2004-4532, because the control characteristic of a light source is set the same as the control characteristic of a video signal, there is a possibility that the light source and the screen image are visually not optimized. Furthermore, in the technology described in JP-A-2004-282377, it is difficult to appropriately suppress a flicker due to light control.